Chromatography Finds a Use for Fiddle-Leaf Fig Waste

Growing plants is a method we can use to redress some of the damage we have done to the environment. Plants produce oxygen and reduce global warming by acting as carbon sinks. Trees and plants can also help stabilize soils and prevent landslips, which with the prospect of increased spells of wet weather due to climate change could be very useful.

Roadside trees, more than a pretty sight

There is also some research to suggest that trees can reduce air pollution when they are planted alongside roads in towns and cities. The relationship between trees and air pollution is not straightforward, and care must be taken in how the trees are planted. If the canopy is too dense it can reduce air flows, meaning that polluted air gets trapped at a low level. This can mean that pollution levels are actually higher. But with careful planting, trees can help to reduce roadside air pollution, increasing the quality of air that we breath.

One type of tree that is used to line roadsides across the world is the Fiddle-leaf fig or ficus lyrata, a member of the fig family that is native to western Africa. The Fiddle-leaf fig can start life as a banyan fig, which is a fig that starts out as an epiphyte. An epiphyte is a plant that starts out growing on another plant. Its seed might germinate in a crack in the bark of another tree, it then sends roots down to the ground which can envelope the host, slowly taking over.

Finding use for fig tree waste

Trees, like most living organisms produce organic waste. A recent paper published in the Jurnal Bahan Alam Terbarukan reports on research carried out in Indonesia that looked at the use of organic waste from Fiddle-leaf fig trees. The organic waste used in the research was dried twigs and leaves that had fallen from the tree. They were particularly interested in the use of the waste as a food preservative after a pyrolysis process.

Pyrolysis is simply a heating process usually in a limited amount of oxygen - it is used in many industries to convert solids into liquids, gases or other solids. In this research the team would look to use the liquid product of pyrolysis. After collection, the leaves were cleaned and dried for 3 days and cut into smaller parts. The leaves then underwent a pyrolysis process at various temperatures. The team collected the resultant liquid.

The liquid product was analysed using GC-MS to determine the compounds formed in pyrolysis. The following article discusses the use of GC-MS to analyse plant materials, Rapid Determination of Strawberry Flavour Integrity using Static Headspace-Selected Ion Flow Tube Mass Spectrometry. The team report that the pyrolysis liquid could be used as a biofuel due to gasoline and kerosene products. But it also has the potential to be used as a food preservative due to carboxylic acid compounds in the liquid.